Foundation January 2021 Paper 2 Q5
5 Here is a number machine.

(a) Work out the output when the input is 7 (1)
(b) Work out the input when the output is 160 (2)
When the input is \(n\), the output is \(P\).
(c) Find a formula for \(P\) in terms of \(n\). (2)
| Scheme | Marks |
|---|---|
| 13 | B1 |
| (1) |
| Scheme | Marks |
|---|---|
| 160 × 2 (=320)or “160 × 2” – 5 or “160 × 2 – 5” ÷ 3 | M1 |
| 105 | A1 |
| (2) |
Notes
M1: One correct inverse operation used
| Scheme | Marks |
|---|---|
| \(P = \dfrac{3n + 5}{2}\) | B2 |
| (2) | |
| (5 marks) |
Notes
B2: oe (B1 for \(\dfrac{3n + 5}{2}\) oe or \(P = 3n + 5 \div 2\)
or for \(P\) = a formula including \(n\) with 2 operations correct eg \(P = 3n + 5\) or for \(n = \dfrac{2P - 5}{3}\) or \(P = \dfrac{2n - 5}{3}\))